A series of experiments on ERP (Event Related Potentials) manifestations of the processes involved in the short-term storage of auditory sensory information will investigate how the brain accomplishes these cognitive processes and also how to relate information obtained from such ERP study of the brain to psychological theories of the same phenomena. The experiments will examine: (1) the persistence of auditory sensory memory; (2) the minimum stimulus duration required for the memory to form a representation of a stimulus (3) the kind of stimulus information that can be coded by the memory; (4) the capacity of the memory; (5) the operation of the comparator mechanism; and (6) the possible effect of attention on this memory.